Integrate LLVM at llvm/llvm-project@4964d75d7078
Integrate LLVM at llvm/llvm-project@4964d75d7078

Updates LLVM usage to match
[4964d75d7078](https://github.com/llvm/llvm-project/commit/4964d75d7078)

PiperOrigin-RevId: 330713009

google-research/structured-additive-IR,google-research/structured-additive-IR